(CNN)A shooter opened fire at a church in the Northern Caucasus region of southern Russia on Sunday, killing five people and wounding two others, authorities said, according to state media.
5 killed in church shooting in Dagestan
The incident took place at a church in Kizlyar in the restive Russian republic of Dagestan.
Police responded, traded fire with the shooter and killed him, the authorities said. Two officers were injured in the gunfight, they said.
ISIS later claimed responsibility for Sunday's shooting through the ISIS-affiliated Amaq media wing and in a statement that circulated on social media, but provided no evidence to support the claim.
The shooting occurred during Maslenitsa, a festival celebrated in Russia that is full of dancing, lots of pancakes and carnival-like festivities.
Russian state news agency Tass spoke to a law enforcement source who said "the unknown person opened fire on people celebrating Maslenitsa."
Kizlyar Mayor Alexander Shuvalov was quoted by Tass as saying the attacker opened fire on "people after leaving the service."
It was not immediately known who was behind the attack.
Dagestan and its neighbor Chechnya have been wracked by separatist and Islamic violence in recent years.